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What I was trying to show here was that reflections don't fade as a result
of reflective properties (not counting variable reflection, whereby the
reflection fades with the viewing angle). The intensity of light does fade
over distance (1/r^2), the energy stays the same but it is spread over a
larger area:
http://imagine.gsfc.nasa.gov/YBA/M31-velocity/1overR2-more.html,
http://www2.ncsu.edu/ncsu/pams/science_house/CBLable/resources.html
Thus, making objects further away appear less bright. POVRay can do light
fading, but, as the docs state, it is only applied to direct illumination
from light sources, reflected or diffuse light does not get attenuated. If
there is any fading of a reflection as the objects distance increases, this
is why, it is not a reflective property, but a light property and should be
extended to the whole scene, not just reflected images. I was trying to use
a black fog to simulate this effect, I haven't put too much thought into it
yet as to the realism, but perhaps I will and post some of my results and
conclusions at a later time.
But, as always, feel free to comment on or dispute this if you feel I am
mistaken in my assumptions, as I promote the spreading of knowledge, not
ignorance and I do appreciate any input or illumination on the matter, pun
intended ;).
-tgq
"Kari Kivisalo" <ray### [at] engineer com> wrote in message
news:3BD488F1.AA0F3F21@engineer.com...
> Trevor Quayle wrote:
> >
> > as an equally illuminated object gets further from
> > the camera, it does not fade (which in reality, it should if direct
light
> > gets attenuated
>
> No, this is not what happens in reality. The energy arriving
> from an object when viewed through a constant space angle stays
> the same because the observed area (and energy) on the object
> increases when viewed from greater distance. The 1/r^2 attenuation
> and increase of observed area cancel each other out. The brightness
> (pixel values) of surfaces is not a function of distance.
>
>
> _____________
> Kari Kivisalo
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